Risk Factors for Cold Sores (Herpes Simplex Type 1)

A risk factor is something that increases your likelihood of getting a disease or condition.

It is possible to develop cold sores with or without the risk factors listed below. However, the more risk factors you have, the greater your likelihood of developing cold sores.

The viruses that cause cold sores are easily spread. They come out of the skin and are “shed” from the site of the cold sore for 1-2 days before the sore appears. Then the virus is in the fluid of the cold sore blisters.

Once you have a herpes simplex infection, cold sores often form because of stress or illness. Some may form without an identifiable trigger.

Risk Factors for Becoming Infected With Herpes Simplex 1 Virus

Exposure to Someone With Cold Sores

Herpes simplex virus type 1 (HSV-1) can be spread by close contact with someone who has a cold sore. It can also be spread through personal items that are contaminated with the virus such as razors, towels, or eating utensils. Kissing or sharing personal items with a person who has a cold sore will increase your risk of getting HSV-1. The virus can also be spread to the genital area during oral sex. People with cold sores should not perform oral sex on their partners. The virus can be spread even when no cold sores are present.

Age

Infants and young children up to three years old have an increased risk of being exposed to HSV-1.

Risk Factors for Developing Cold Sores Once You Have a Herpes Simplex Infection

Exposure to Sunlight

Exposure to sunlight or other ultraviolet light is a common trigger for cold sores.

Physical Stress and Illness

Stress on the body due to illness or excessive exercise can weaken the body’s immune system. This can lead to an outbreak of cold sores. Common examples of stress or illness include:

Medication, such as steroids, or illness, such as
HIV
, that suppresses the immune system

Excessive exercise

Emotional Stress

Cold sore outbreaks commonly occur during times of emotional stress. The type of stress that activates cold sores is typically negative stress, instead of stress due to positive or normal life-changing events.

Revision Information

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.

Herpes: Causes and risk factors. American Academy of Family Physicians Family Doctor website. Available at:
http://familydoctor.org/familydoctor/en/diseases-conditions/herpes/causes-risk-factors.html. Updated December 2010. Accessed March 20, 2013.